This section provides background information related to the present disclosure which is not necessarily prior art.
A control circuit for controlling a power switch in an AC-DC power converter may include a voltage control loop to control an output DC voltage and a current control loop to shape an AC input current. The control circuit may generate a current reference for the current control loop based on a signal from the voltage control loop. The current control loop generates a switching signal to control the power switch based on the current reference.
The signal received from the voltage control loop may include ripple that can distort the current reference which, in turn, distorts the AC input current. To reduce the ripple, a bandwidth of the voltage control loop may be reduced well below the ripple frequency.